Full panel easy open end

ABSTRACT

In a full open end closure for a container having a peripheral score defining a removable section in the panel of the end closure, a novel combination of structural features is provided to stiffen the portion of the panel encompassing the peripheral score. The peripheral score is comprised by a pop section at the forward end of the removable section which merges into adjoining start tear sections of the peripheral score, a detach section at the rearward end of the removable section which merges into adjoining minimum tear sections of the peripheral score, and full diameter tear sections at the sides of the removable section which merge into adjoining start tear and minimum tear sections. The end panel also has a hinge score adjacent to the pop section of the peripheral score and a securement for attaching an opening tab to the removable section of the panel, the attachment being positioned between the peripheral score and the hinge score. The novel structural features in the panel are comprised by an inner score in the removable section which runs substantially parallel to the peripheral score, has a depth shallower than that of the peripheral score, and adjoins and merges at its ends into the ends of the hinge score, and stiffening means in the removable section in the form of a ridgelike feature projecting outwardly from the removable section between the peripheral and inner scores both at the forward and rearward ends of the removable section. The novel combination of the inner score with the stiffening means provide a line along the inner score about which the central portion of the removable section is allowed to flex when subjected to forces directed against the removable section to thereby reduce the susceptibility of the peripheral score to abuse and premature fracture which would occur if the removable section should flex on a line along the peripheral score.

United States Patent Batchelar et al.

Primary Examiner-George T. Hall Attorney-Robert P. Auber, George P.Ziehmer, Leonard R. Kohan and John R. Flanagan [57] ABSTRACT In a fullopen end closure for a container having a peripheral score defining aremovable section in the panel of the end closure, a novel combinationof structural features is provided to stiffen the portion of the panelencompassing the peripheral score. The

peripheral score is comprised by a pop section at the forward end of theremovable section which merges into adjoining start tear sections of theperipheral 7 score, a detach section at the rearward end of theremovable section which merges into adjoining minimum tear sections ofthe peripheral score, and full diameter tear sections at the sides ofthe removable section which merge into adjoining start tear and minimumtear sections. The end panel also has a hinge score adjacent to the popsection of the peripheral score and a securement for attaching anopening tab to the removable section of the panel, the attachment beingpositioned between the peripheral score and the hinge score. The novelstructural features in the panel are comprised by an inner score in theremovable section which runs substantially parallel to the peripheralscore, has a depth shallower than that of the peripheral score, andadjoins and merges at its ends into the ends of the hinge score, andstiffening means in the removable section in the form of a ridgelikefeature projecting outwardly from the removable section between theperipheral and inner scores both at the forward and rearward ends of theremovable section. The novel combination of the inner score with thestiffening means provide a line along the inner score about which thecentral portion of the removable section is allowed to flex whensubjected. to forces directed against the removable section to therebyreduce the susceptibility of the peripheral score to abuse and prematurefracture which'would occur if the removable section should flex on'aline along the peripheral score.

6 Claims, 5 Drawing Figures Feb. 6, 1973 FULL PANEL EASY OPEN ENDBACKGROUND OF THE INVENTION One of the more important recentdevelopments in the can making industry is the trend toward scoredself-opening cans which can be opened by means of an opening tab whichis secured to the can. The most common form of such a can is the beerand beverage can in which the product is dispensed through acomparatively small hole which is opened in the can end when the openingtab is lifted to tear away a small removable section which is defined bya score line in the end panel.

Another form is the full-open can in which a score is impressed in theend panel proximate to the periphery of the end panel to permit itscomplete removal. Such full-open cans are suitable for use in thepackaging of solid or chunky products such as processed or frozen meats,fishes, vegetables and fruits, and frozen juices which are to be removedfrom the container in their entirety. They are also desirable for thepackaging of products which are customarily removed by insertion of aninstrument or the fingers of the user into the container. Examples ofsuch products are candy, shelled nuts, meats and coffee.

In the area of scored self-opening cans, any score defining aremovablesection in the end panel constitutes a line of metal weaknessin the end panel.

When the removable section includes a large surface area of the endpanel, as in the case of a full-open end where it covers substantiallythe whole endpanel, undesirable and uncontrollable forces directedagainst the removable section tend to cause it to flex, relative to theremainder of the end panel, along this line of metal weakness, theperipheral score. Such forces arise in the case of containers forprocessed foods. During the cooking of food in the container, internalpressures bulge the removable section and thereby cause the removablesection to flex along the peripheral score. Later when the food coolsand a partial vacuum condition is created within the container, theremovable section flips to a concave position. Again, the removablesection flexes along the peripheral score. The flexing of the removablesection along the peripheral score places a severe strain on theweakened residual metal beneath the score, making it susceptible toabuse, leakage and premature fracture.

The present invention provides a novel combination of structuralfeatures on a full open end panel which overcomes the problem of theremovable panel flexing along the peripheral score and, thereby, reducesthe susceptibility of the peripheral score to abuse and prematurefracture. This novel combination is comprised by an inner scoreimpressed in the removable section of the end panel substantiallyparallel to the peripheral score and a ridge-like feature projectingoutwardly from the removable section between the peripheral and innerscores at the forward and rearward ends of the removable section. Theends of the inner score novelly merge with the ends of the adjoininghinge score. The ridge-like features stiffen the metal between theperipheral and inner scores at the forward and rearward ends of theremovable section and thereby resists the flexing of the removablesection along the peripheral score. The inner score, which is shallowerthan the peripheral score, promotes and provides a different flex pointfor the removable: section and, in such manner, contributes to theprevention of flexing along the peripheral score.

SUMMARY OF THE INVENTION A full open end closure for a container, havinga peripheral score defining a removable section in the end panel and ahinge score adjacent the peripheral score at the forward end of theremovable section, has an inner score which is shallower than theperipheral score and runs substantially parallel to the peripheral scorewith the ends of the inner score adjoining and merging into the ends ofthe hinge score. Also, the end closure has a ridge-like feature whichprojects outwardly from the removable section between the peripheral andinner scores at the forward and rearward ends of the removable section.This novel combination of an inner score and ridge-like featuresstiffens the metal of the end panel between the inner and peripheralscores to resist the flexing of the removable section along theperipheral score and, instead, permits the removable section to flexalong the inner score.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. I is a plan view of an endclosure made in accordance with the present inventionj FIG. 2 is anenlarged, fragmentary view of the forward end of the removable sectionof the end closure shown in FIG. 1 with the opening tab omitted;

FIG. 3 is an enlarged, fragmentary view partially in section takensubstantially along lime 3-3 of FIG. 1;

FIG. 4 is an enlarged, fragmentary view partially in section takensubstantially along "line 44 of FIG. 1; and

FIG. 5 is a schematic illustration of the various sections of theperipheral score of the end closure shown in FIG. 1.

DESCRIPTION OF THE PREFERRED EMBODIMENT An end closure, generallydesignated 10, embodying the present invention is shown in FIGS. 1 and3. Preferably, it is rectangular and made of aluminum, tinplate, orother rupturable material. The end'closurel0 includes a peripheraloutwardly extending curled flange 12 which may be interfolded with theend flange of a can body (not shown) to form an end seam (not shown).The peripheral flange 12 merges into an annular countersink wall 14which extends downwardly from the peripheral flange 12 to animperforatecentral end panel 16.

Impressed in the top surface of the central end panel 16 is a score,generally designated 18, which defines a removable section 20 whichbecomes detached from the end closure 10 when the score 18 is completelyruptured. The score 18 is close to the: periphery of the central endpanel 16 so that it defines a removable section 20 which is almost aslarge as the central end panel 16. The peripheral score 18, asschematically illustrated in FIG. 5, is comprised by a pop section 22 atthe forward end of the removable section 20 which merges into adjoiningstart tear sections 24. The rearward ends of the start tear sections 24merge into adjoining substantially full diameter tear sections 26. Therearward ends of the full diameter tear sections 26 merge into adjoiningminimum tear sections 28 whose rearward ends merge into a detach section30 at the rearward end of the removable section 20.

In order to provide means for rupturing the peripheral score 18, anopening tab 32 is fastened to the removable section 20 at a locationadjacent to the pop section 22 of the peripheral score 18 by a hollowrivet 34 formed integral with the removable section 20. The opening tab32 includes a web portion 36 through which the rivet 34 passes, a handleportion 38 rearwardly of the web portion 36 and a nose portion 40forwardly of the web portion 36 which is urged downwardly when thehandle portion 38 is raised to initiate pop or rupture of the popsection 22 of the peripheral score 18.

The removable section 20 has a mustache or hinge score, generallydesignated 42, impressed therein having a curved central portion 44which passes immediately behind the rivet 34 which portion 44 initiallyruptures during the first stage of the upward rock of the opening tab 32to allow a venting of the container thereby equalizing the internalpressure of the container and the atmosphere pressure on the top of thecentral end panel 16. The removable section 20 further has severalparallel and downwardly projecting beads 46 formed therein which promotethe formation of a bend in the removable section 20 in a direction whichis generally perpendicular to the direction in which the opening tab 32is moved, to facilitate the progressive rupture of the peripheral score18. The advantages of providing the mustache score 42 are disclosed ingreater detail in the application for Letters Patent, Ser. No. 728,518,now U.S. Pat. No., 3,544,025, and do not form any part of the presentinvention. The advantages of providing the beads 46 are disclosed ingreater detail in U.S. Pat. No. 3,478,918 which issued on Nov. 18, 1969and do not form any part of the present invention.

As shown in FIGS. 1, 2 and 3, the end closure is novelly provided withan inner score, generally designated 48, impressed in the removablesection which runs generally parallel to the peripheral score 18, havinga depth shallower than that of the peripheral score 18 and which may beequal to that of the hinge score 42, and ridge-like features, generallydesignated 50, which project outwardly from the removable section 20between the peripheral score 18 and the inner score 48 at the forwardand rearward ends of the removable section 20. The ends 52 of the innerscore 48 novelly merge into the adjoining ends 54 of the hinge score 42at a location, generally designated, 56. The ridge-like features 50stiffen the metal of the removable section 20 between the peripheralscore 18 and the inner score 48 at the forward and rearward ends of theremovable section 20 and thereby resists the flexing of the removablesection 20 along the peripheral score 18. Further, the inner score 48contributes to the ability of the ridge-like features 50 to stiffen themetal of the removable section 20 between the peripheral score 18 andthe inner score 48 by providing a different flex point for the removablesection 20, that being along the inner score 48. The ridgelikestiffening features 50 are formed from the excess metal in the removablesection 20 which is provided during the formation of the peripheralscore 18 and the inner'score 48.

While the inner score 48 is described above as running generallyparallel to the peripheral score, as shown in FIGS. 1, 3 and 4 thecenter-to-center distance between the scores 18, 48 is greater at theforward and rearward ends ofthe removable section 20 than at the sidesof the removable section. The provision of an inner score per se, whichis shallower than the peripheral score, for the purpose of anti-fractureis disclosed by U.S. Pat. No. 3,406,866 which issued on Oct. 22, 1968and does not form any part of the present invention. As disclosed in theaforementioned patent, the practical range of the center-to-centerspacing between the peripheral score and the inner score, in order forthe inner score to function as an anti-fracture score, is from 0.050inch to 0.125 inch with the optimum spacing being on the order of 0.080inch. In the present invention, the center-to-center spacing between theperipheral score 18 and the inner score 48 at the forward and rearwardends of the removable section 20 is above the aforementioned range,or,.greater than 0.125 inch. Therefore the inner score 48 of the presentinvention, at the forward and rearward ends of the removable section 20,does not function as an anti-fracture score. In one practical example ofan end closure incorporating the present invention, the center-to-centerspacing between the peripheral score 18 and the inner score 48, at theforward and rearward ends of the removable section 20, is about 0.194inch. In this example, the hinge and inner scores have equal residualmetal thicknesses of about 0.005 inch, which thickness is generallyabout 0.001 inch greater than the residual metal thickness of theperipheral score, that being 0.004 inch.

It is thought that the invention and many of its attendant advantageswill be understood from the foregoing description and it will beapparent that various changes may be made in the form, construction'andarrangement of the partswithout departing from the spirit and scope ofthe invention or sacrificing all of its material advantages, the formhereinbefore described being merely a preferred embodiment thereof.

We claim:

1. In a full open container panel having a peripheral score defining aremovable section in said panel, said score being comprised by a popsection at the forward end of said removable section which merges intoadjoining start tear sections of said score, a detach section at therearward end of said removable section which merges into adjoiningminimum tear sections of said score, and full diameter tear sections atthe sides of said removable section which adjoin and merge into thestart tear and minimum tear sections, a hinge score adjacent to said popsection of said peripheral score, and a securement for attaching anopening tab to said removable section positioned between said peripheralscore and said hinge score, the improvement comprismg:

an inner score in said removable panel running generally parallel tosaid peripheral score and having a depth shallower than said peripheralscore and wherein the center-to-center distance between said peripheraland inner scores at the forward and rearward ends of said removablesection is greater than 0.125 inch; and

stiffening means in said removable section between against saidremovable section to thereby reduce the said peripheral and inner scoresat the forward and susceptibility of said peripheral score to abuse andprerearward ends of said section, said stiffening mature fracture. meanscomprising a r dg f atu at both the 4. The full open container panel ofclaim 3 wherein P 'f ends of Said fmovable 5 said stiffening meanscomprises a ridge-like feature at P l outwardly from 531d removable boththe forward and rearward ends of said removable Section and fofmed f mexcfiss metal m 531d section projecting outwardly from said removablesecremovable Seem) whlch provided by the forma' tion and formed fromexcess metal in said removable tion i peripheralandinnir section whichis provided by the formation of' said 2. The fu open container pane o carm 1 wherein Peripheral and inner scores :5 9:" g i g z g 33 fg g i. 5.The full open container panel of claim 4 wherein a 1 C res a e Orwar anre wa en 8 o the center-to-center distance between said peripheral saidremovable section is greater than 0.125 inch.

3 The fun 0 en container and of claim 1 wherein and inner scores at theforward and rearward ends of i p p said removable section is greaterthan 0.125 inch.

said inner score and adjacently positioned stiffening l5 means at theforward and rearward ends of said fun 9 contamer f f of clam l Wheremremovable section cooperate to provide a line along the ends 9 Scoreadjom and merge the said inner score about which said removable sectionis ends of Sand hmge Score allowed to flex when subjected to forcesdirected

1. In a full open container panel having a peripheral score defining aremovable section in said panel, said score being comprised by a popsection at the forward end of said removable section which merges intoadjoining start tear sections of said score, a detach section at therearward end of said removable section which merges into adjoiningminimum tear sections of said score, and full diameter tear sections atthe sides of said removable section which adjoin and merge into thestart tear and minimum tear sections, a hinge score adjacent to said popsection of said peripheral score, and a securement for attaching anopening tab to said removable section positioned between said peripheralscore and said hinge score, the improvement comprising: an inner scorein said removable panel running generally parallel to said peripheralscore and having a depth shallower than said peripheral score andwherein the center-to-center distance between said peripheral and innerscores at the forward and rearward ends of said removable section isgreater than 0.125 inch; and stiffening means in said removable sectionbetween said peripheral and inner scores at the forward and rearwardends of said section, said stiffening means comprising a ridge-likefeature at both the forward and rearward ends of said removable sectionprojecting outwardly from said removable section and formed from excessmetal in said removable section which is provided by the formation ofsaid peripheral and inner scoreS.
 1. In a full open container panelhaving a peripheral score defining a removable section in said panel,said score being comprised by a pop section at the forward end of saidremovable section which merges into adjoining start tear sections ofsaid score, a detach section at the rearward end of said removablesection which merges into adjoining minimum tear sections of said score,and full diameter tear sections at the sides of said removable sectionwhich adjoin and merge into the start tear and minimum tear sections, ahinge score adjacent to said pop section of said peripheral score, and asecurement for attaching an opening tab to said removable sectionpositioned between said peripheral score and said hinge score, theimprovement comprising: an inner score in said removable panel runninggenerally parallel to said peripheral score and having a depth shallowerthan said peripheral score and wherein the center-to-center distancebetween said peripheral and inner scores at the forward and rearwardends of said removable section is greater than 0.125 inch; andstiffening means in said removable section between said peripheral andinner scores at the forward and rearward ends of said section, saidstiffening means comprising a ridge-like feature at both the forward andrearward ends of said removable section projecting outwardly from saidremovable section and formed from excess metal in said removable sectionwhich is provided by the formation of said peripheral and inner scoreS.2. The full open container panel of claim 1 wherein the center-to-centerdistance between said peripheral and inner scores at the forward andrearward ends of said removable section is greater than 0.125 inch. 3.The full open container panel of claim 1 wherein said inner score andadjacently positioned stiffening means at the forward and rearward endsof said removable section cooperate to provide a line along said innerscore about which said removable section is allowed to flex whensubjected to forces directed against said removable section to therebyreduce the susceptibility of said peripheral score to abuse andpremature fracture.
 4. The full open container panel of claim 3 whereinsaid stiffening means comprises a ridge-like feature at both the forwardand rearward ends of said removable section projecting outwardly fromsaid removable section and formed from excess metal in said removablesection which is provided by the formation of said peripheral and innerscores.
 5. The full open container panel of claim 4 wherein thecenter-to-center distance between said peripheral and inner scores atthe forward and rearward ends of said removable section is greater than0.125 inch.